Motown: Rename Ratio and LinearFunction classes

services/media/common/test/timeline_rate_test.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <limits>
+
+#include "mojo/services/media/common/cpp/timeline_rate.h"
+#include "services/media/common/test/test_base.h"
+
+namespace mojo {
+namespace media {
+namespace {
+
+class TimelineRateTest : public TestBase {
+  static uint32_t gcd(uint32_t a, uint32_t b) {
+    while (b != 0) {
+      uint32_t t = a;
+      a = b;
+      b = t % b;
+    }
+    return a;
+  }
+
+ public:
+  // Verifies TimelineRate::Reduce and the constructor, ensuring that the ratio
+  // subject_delta * common_factor / reference_delta * common_factor is reduced
+  // to subject_delta / reference_delta. subject_delta and reference_delta need
+  // to be relatively prime for this to work.
+  void VerifyReduce(uint32_t subject_delta,
+                    uint32_t reference_delta,
+                    uint32_t common_factor) {
+    // Make sure subject_delta and reference_delta are relatively prime.
+    EXPECT_EQ(1u, gcd(subject_delta, reference_delta));
+
+    uint32_t test_subject_delta = subject_delta * common_factor;
+    uint32_t test_reference_delta = reference_delta * common_factor;
+
+    // Make sure the constructor reduces.
+    TimelineRate rate(test_subject_delta, test_reference_delta);
+    EXPECT_EQ(subject_delta, rate.subject_delta());
+    EXPECT_EQ(reference_delta, rate.reference_delta());
+
+    // Test the static method.
+    TimelineRate::Reduce(&test_subject_delta, &test_reference_delta);
+    EXPECT_EQ(subject_delta, test_subject_delta);
+    EXPECT_EQ(reference_delta, test_reference_delta);
+  }
+
+  // Verifies the TimelineRate::Scale methods by scaling value by subject_delta
+  // /
+  // reference_delta and verifying the result.
+  void VerifyScale(int64_t value,
+                   uint32_t subject_delta,
+                   uint32_t reference_delta,
+                   int64_t result) {
+    // Test the instance method.
+    EXPECT_EQ(result,
+              TimelineRate(subject_delta, reference_delta).Scale(value));
+
+    // Test the static method.
+    EXPECT_EQ(result,
+              TimelineRate::Scale(value, subject_delta, reference_delta));
+
+    // Test the operators.
+    EXPECT_EQ(result, value * TimelineRate(subject_delta, reference_delta));
+    EXPECT_EQ(result, TimelineRate(subject_delta, reference_delta) * value);
+    if (subject_delta != 0) {
+      EXPECT_EQ(result, value / TimelineRate(reference_delta, subject_delta));
+    }
+  }
+
+  // Verifies the TimelineRate::Product methods by multiplying the given a and b
+  // rates and checking the result against the expected rate.
+  void VerifyProduct(uint32_t a_subject_delta,
+                     uint32_t a_reference_delta,
+                     uint32_t b_subject_delta,
+                     uint32_t b_reference_delta,
+                     uint32_t expected_subject_delta,
+                     uint32_t expected_reference_delta,
+                     bool exact) {
+    // Test the first static method.
+    uint32_t actual_subject_delta;
+    uint32_t actual_reference_delta;
+    TimelineRate::Product(a_subject_delta, a_reference_delta, b_subject_delta,
+                          b_reference_delta, &actual_subject_delta,
+                          &actual_reference_delta, exact);
+    EXPECT_EQ(expected_subject_delta, actual_subject_delta);
+    EXPECT_EQ(expected_reference_delta, actual_reference_delta);
+
+    // Test the second static method.
+    EXPECT_EQ(TimelineRate(expected_subject_delta, expected_reference_delta),
+              TimelineRate::Product(
+                  TimelineRate(a_subject_delta, a_reference_delta),
+                  TimelineRate(b_subject_delta, b_reference_delta), exact));
+
+    // Test the operator
+    if (exact) {
+      EXPECT_EQ(TimelineRate(expected_subject_delta, expected_reference_delta),
+                TimelineRate(a_subject_delta, a_reference_delta) *
+                    TimelineRate(b_subject_delta, b_reference_delta));
+    }
+  }
+
+  // Verifies the TimelineRaten::Inverse method using the given rate.
+  void VerifyInverse(uint32_t subject_delta, uint32_t reference_delta) {
+    TimelineRate rate(subject_delta, reference_delta);
+    TimelineRate inverse(rate.Inverse());
+    EXPECT_EQ(rate.reference_delta(), inverse.subject_delta());
+    EXPECT_EQ(rate.subject_delta(), inverse.reference_delta());
+  }
+};
+
+// Tests TimelineRate::Reduce and that the TimelineRate constructor reduces.
+TEST_F(TimelineRateTest, Reduce) {
+  VerifyReduce(0, 1, 1);
+  VerifyReduce(1, 1, 1);
+  VerifyReduce(1234, 1, 1);
+  VerifyReduce(1, 1234, 14);
+  VerifyReduce(1, 1, 1234);
+  VerifyReduce(10, 1, 1234);
+  VerifyReduce(1, 10, 1234);
+  VerifyReduce(49, 81, 1);
+  VerifyReduce(49, 81, 10);
+  VerifyReduce(49, 81, 100);
+  VerifyReduce(1, 8, 65536);
+  VerifyReduce(8, 1, 65536);
+}
+
+// Tests TimelineRate::Scale, static, instance and operator versions.
+TEST_F(TimelineRateTest, Scale) {
+  const int64_t int64_min = std::numeric_limits<int64_t>::min();
+  VerifyScale(0, 0, 1, 0);
+  VerifyScale(1, 0, 1, 0);
+  VerifyScale(0, 1, 1, 0);
+  VerifyScale(1, 1, 1, 1);
+  VerifyScale(1, 2, 1, 2);
+  VerifyScale(1, 1, 2, 0);
+  VerifyScale(-1, 1, 2, -1);
+  VerifyScale(1000, 1, 2, 500);
+  VerifyScale(1001, 1, 2, 500);
+  VerifyScale(-1000, 1, 2, -500);
+  VerifyScale(-1001, 1, 2, -501);
+  VerifyScale(1000, 2, 1, 2000);
+  VerifyScale(1001, 2, 1, 2002);
+  VerifyScale(-1000, 2, 1, -2000);
+  VerifyScale(-1001, 2, 1, -2002);
+  VerifyScale(1ll << 32, 1, 1, 1ll << 32);
+  VerifyScale(1ll << 32, 1, 2, 1ll << 31);
+  VerifyScale(1ll << 32, 2, 1, 1ll << 33);
+  VerifyScale(1234ll << 30, 1, 1, 1234ll << 30);
+  VerifyScale(1234ll << 30, 1, 2, 1234ll << 29);
+  VerifyScale(1234ll << 30, 2, 1, 1234ll << 31);
+  VerifyScale(1234ll << 30, 1 << 31, 1, TimelineRate::kOverflow);
+  VerifyScale(1234ll << 30, 1ll << 31, (1ll << 31) - 2,
+              (1234ll << 30) + 1234ll);
+  VerifyScale(int64_min, 1, 1, int64_min);
+  VerifyScale(int64_min, 1, 2, int64_min / 2);
+  VerifyScale(int64_min / 2, 2, 1, int64_min);
+  VerifyScale(int64_min, 1000001, 1000000, TimelineRate::kOverflow);
+}
+
+// Tests TimelineRate::Product, static and operator versions.
+TEST_F(TimelineRateTest, Product) {
+  VerifyProduct(0, 1, 0, 1, 0, 1, true);
+  VerifyProduct(1, 1, 1, 1, 1, 1, true);
+  VerifyProduct(10, 1, 1, 10, 1, 1, true);
+  VerifyProduct(4321, 1234, 617, 4321, 1, 2, true);
+  VerifyProduct(1234, 4321, 4321, 617, 2, 1, true);
+  VerifyProduct(1ll << 31, (1ll << 31) - 1, (1ll << 31) - 1, 1ll << 31, 1, 1,
+                true);
+  VerifyProduct(1ll << 31, (1ll << 31) - 1, (1ll << 31) - 2, 1ll << 31,
+                0x7ffffffe, 0x7fffffff, false);
+}
+
+// Tests TimelineRate::Inverse.
+TEST_F(TimelineRateTest, Inverse) {
+  VerifyInverse(1, 1);
+  VerifyInverse(2, 1);
+  VerifyInverse(1, 2);
+  VerifyInverse(1000000, 1234);
+  VerifyInverse(1234, 1000000);
+}
+
+}  // namespace
+}  // namespace media
+}  // namespace mojo